1. Field of the Invention
The present invention relates to a projector screen for an image display, and more particularly, to a projector screen having an improved structure allowing a wider horizontal viewing angle.
2. Description of the Related Art
An image projection system, such as a projection television or a video projector, generates an image using an image formation medium, such as a small cathode ray tube (CRT), a liquid crystal display (LCD) or a polymer dispersion LCD (PDLCD), and magnifies and projects the image onto a large screen using a projection lens.
The image projection system is in great demand since it meets the demands of consumers who prefer a large screen.
In the operation of an image projection system, an image is projected from an image source to a screen, and the projected image is viewed by a viewer in front of the screen. When there are a large number of viewers, they must be positioned in many positions in front of the screen, and therefore, the image must be projected to have a wide viewing angle so that the image can be viewed from many different positions.
Referring to FIG. 1 showing a conventional projector screen, the screen includes a Fresnel lens 11 for collimating a divergent light emitted from a projection lens (not shown) of a projecting device, to display an image having a wide viewing angle and uniform luminance. A lenticular lens 12 functions as a light spreader for spreading a collimated light from the Fresnel lens 11 and forming an image is installed in front of the Fresnel lens 11. The lenticular lens 12 includes a plurality of cylindrical lens elements 13 that are arranged parallel and adjacent to each other.
A protrusion 14 for preventing interference between lights diverged by convex surfaces 13a of the adjacent lens elements 13 is formed to a predetermined height on the joint portion of the lens elements 13 in the front portion of the lenticular lens 12. A black stripe 14a coated with black ink is formed on the front surface of the protrusion 14, so that the contrast of an image is improved.
A screen protection panel (not shown) made of an acrylic resin is installed in front of the lenticular lens 12.
In the above-described conventional projector screen, since the protrusion 14 protrudes forward more than the convex surfaces 13a of the lens elements 13, the angle by which light is spread is limited by the protrusion 14 as shown in FIG. 2. Therefore, a horizontal view angle with respect to an image on a screen is also limited.